1. Field of the Invention
The present invention relates to tubing sealers and, more particularly, to a radio frequency generator for generating radio frequency power to melt and weld a seal across plastic tubing.
2. Description of Related Art
There is a continual existing need for blood donors in order to meet the day to day hospital demand for blood. Consequently, many private organizations, whether or not affiliated with hospitals, have arisen for the sole purpose of collecting blood. In order to obtain sufficient quantities of blood, these organizations must visit locations having a high concentration of blood donors. Schools, office buildings, factories and the like are prime candidates for a high density of blood donors. To effect collection, all the equipment necessary to collect the donated blood must be transported to the location. This places a premium on portability and ease of use of the equipment.
Normally, the blood is drawn from a donor through flexible tubing extending into a plastic blood collection bag. Once the bag is filled to its capacity, the tubing must be sealed to prevent leakage and, more importantly, prevent contamination and deterioration of the collected blood. After collection, the blood must be typed and tested under various criteria. To provide a representative supply of blood for these typing and test purposes, a plurality of segments of the tubing are sealed from one another to provide a plurality of segregable sealed samples which are opened only for typing and testing purposes.
Because of the required mobility and rapid blood collection procedures, any and all equipment used must be specifically designed for compact storage, minimum reliance upon support facilities at the blood collection location, minimum operating and setup times and ease of operability. A hand held sealer suitable for this purpose is described in U.S. Pat. No. 4,013,860, which patent is assigned to the present assignee. It discloses a hand operated sealer having a pair of jaws for compressing the tubing while simultaneously applying radio frequency energy to melt the tubing and form a weld thereacross to effect a seal. The described hand sealer is portable and has been successfully used throughout the world for many years. U.S. Pat. No. 4,186,292, assigned to the present assignee, describes a tubing sealer usable at a fixed location to perform seals commensurate with requirements of a production line. U.S. Pat. No. 4,496,819, assigned to the present assignee, describes various configurations of jaws usable in a hand held or a fixed based sealer for the purpose of applying radio frequency energy across a length of tubing to be welded. U.S. Pat. No. 4,490,598, assigned to the present assignee, describes a sealer usable at a fixed location for effecting a plurality of seals in a length of blood collection tubing. The teachings and details set forth in these patents are incorporated herein by reference.